Prime Factorization

Q.

Express $429$ as product of its prime number.

Q.

Find the prime factorization of $20570$

Q. The prime factorization of 450 is

1. 2×3×3×5×5
2. 2×3×3×7×7
3. 2×2×3×3×5

Q.

144 expressed as a product of its primes is ___.

1. $2\times 2\times 2\times 2\times 3\times 3$

2. $2\times 2\times 2\times 2\times 3\times 3\times 3$

3. $3\times 3\times 3\times 3\times 3\times 3$

4. $2\times 2\times 2\times 2\times 2\times 2$

Q. The prime factorization of 350 is

1. 2 × 3 × 3 × 5 × 7
2. 2 × 5 × 5 × 7
3. 2 × 3 × 5 × 7

Q. What is the prime factorization of 840?

1. 2 × 2 × 2 × 3 × 3 × 7
2. 4 × 5 × 6 × 7
3. 2 × 3 × 3 × 7 × 7
4. 2 × 2× 2 × 3 × 5 × 7

Q.

42 and 36 are co-prime numbers.

1. True

2. False

Q.

Find the prime factorization of $9000$

Q.

How many times 3 occurs in prime factorization of 162 ?

1. 3
2. 2
3. 4
4. 5

Q.

Is $343$ a prime number?

Q.

Write the prime factors of $28\mathrm{and}36$ through the division method.

Q. What isthe missing number in the factor tree?

1. 40
2. 45
3. 35
4. 25

Q. 2 × 2 × are the prime factors of 108.

1. $3\times 3\times 3$
2. $3\times 3\times 2$
3. $3\times 4\times 3$

Q. In which of the following cases, the first number is a factor of the second number?

1. 4, 38
2. 5, 33
3. 6, 52
4. 8, 96

Q.

To find the prime factors of any given number we divide the number by ___ till we get 1.

1. odd numbers

2. even numbers

3. prime numbers

4. composite numbers

Q. The prime factorisation of $150$ isFind the missing number.

1. 5
2. 6
3. 2

Q.

What is co-prime number

Q.

Find the prime factors of $105.$Arrange the factors in ascending order and find the relation between two consecutive prime factors.

Q. Which of the following is the prime factorization of $63?$

1. $3\times 21$
2. $7\times 9$
3. $1\times 63$
4. $3\times 3\times 7$

Q. Complete the multiplication chart given here.



Look at the green boxes in the chart. These show how we can get 12 by multiplying different numbers.

12

4 × 3 6 × 2 1 × 12

12 = 4 × 3, so 12 is a multiple of both 4 and 3. 12 is also a multiple of 6 and 2, as well as 12 and 1. We say 1, 2, 3, 4, 6, 12 are factors of 12.

• What are the factors of 10? _________

10

5 × 2 _ _ _

Can you do this from the chart?
• What are the factors of 36? ________
• Find out all the factors of 36 from the multiplication chart.
• What is the biggest number for which you can find the factors form this chart?
• What can you do for numbers bigger than that?

Q.

Write the prime factorisation of each of the following numbers : $441$

Q. The prime factorisation of $100$ is

Find the missing number.

1. 25
2. 50
3. 100

Q.

30 as a product of its prime factors is ___

1. $2\times 3\times 5$

2. $3\times 3\times 3$

3. $2\times 3\times 3$

4. $2\times 2\times 5$

Q.

Write the greatest $4$ digit number and express it in terms of its prime factors.

Q. Which prime factors of 384 are missing?

1. 2, 2, 2, 2, 3
2. 2, 2, 3, 3, 5
3. 1, 2, 3, 5, 9
4. 2, 2, 3, 3, 7

Q. What are the missing ornaments from the given factor tree?

1. 
2. 
3. 
4. 

Q. A list consists of the following pairs of numbers:

(i) 51, 53; 55, 57; 59, 61; 63, 65; 67, 69; 71, 73

Categorize them as pairs of:

(i) co-primes
(ii) primes
(iii) composites

Q.

Which of the following is a prime number?

1. 9
2. 13
3. 18
4. 21

Q.

Write the prime factorisation of each of the following numbers : $160$

Q. For which of the following numbers, all its digits are its factors?

1. 19
2. 25
3. 35
4. 135